Refrigeration



Och 1932- F. D. PELTIER ET AL 1,884,186

REFRIGERATION Filed Dec. 6, 1926 2 Sheets-Sheet 1 J W 4 T 5 j INVENT /02 Q2 2 p %IATTORNEY Oct. 25, 1932.

F. D. PELTIER ET AL REFRIGERATION Q Q a:

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Q i I "II I I' ENTOR @w 19/; ATT'ORNEY Patented Oct. 25, 1932 UNITEDSTATES PATENT OFFICE FRANK DESNOYERS PELTIER AND CLYDE EDWARD PLOEGER, FEVANSVILLE, INDIANA,

ASSIGNORS, BY MESNE ASSIGNMENTS, TO SERVED, INC 01 NEW YORK, N. Y., ACOR- I PORATION OF DELAWARE REFRIGERATION Application filed December 6,1926. Serial No. 152,902.

Our invention relates to refrigerating apparatus and more particularlyto apparatus employing a compressor and the flooded type of evaporator.

Amongst the objects of the invention are 5.to afford an improvedlubrication; to assure v a uniform flow of lubricant to the compressor;

to provide a novel, improved, and highly effected means of causing flowof lubricant; to provide a novel process of refrigeration; 1 topositively return lubricant from a float valve chamber to the compressorand, in general, to improve the operation of refrigerating apparatuswherein a lubricant is used.

'ith the above and other objects in view,

the invention consists in the novel features of construction,arrangement of parts and combination of elements hereinafter describedand such variations thereof as fall within the scope and spirit of theinvention and method and process involved in the operation of suchapparatus.

The invention is described with reference to the accompanying drawingson which Fig. 1 shows more or less diagrammatically a system embodyingone form of the invention; Fig. 2 is an enlarged view in section of aportion of the apparatus shown in Fig. 1; Fig. 3 shows a modified formof the invention adaptable to different conditions as will more fullyhereinafter appear; Fig. 4 shows a still further modification for astill further variation of conditions, and Fig. 5 shows a modified formof pressure reducing device forming part of the invention.

Referring more particularly to Fig. 1, a refrigerating apparatus orsystem is shown which includes a motor 2, a compressor 3 driven by themotor. a condenser 4 supplied with refrigerant by the compressor, anevaporator designated generally by reference character 5, and a controlswitch 6. The condenser is connected to supply liquid refrigerant to theevaporator and the evaporator is connected with the suction side of thecompressor for passage of evaporated refrigerant to the compressor.Member 6 is an electric switch controlling the operation of the motor inresponse to pressure within the suction line to the compressor. Switchesof this 50 type responsive to various agencies are known per se. Theabove constitutes a layout to which our invention is applicable but itis to be understood that we are not limited to the system thusdiagrammatically illustrated.

Various types of control may be used, the condenser may be cooled inanyway and, as will be apparent, the invention is not limited to aparticular system.

Referring more particularly to Fig. 2, reference character 10 designatesthe casing of a float chamber. This float chamber may constitute aportion of the evaporator 5. The casing is provided with an end cover 11and an end cover 16. In cover 11 is an opening 13 arranged to beconnected with the discharge side of the compressor and with thecondenser which is interposed in series between opening 13 and thecompressor discharge. Cover 11 is also equipped with an opening 14 whichis connected to the inlet of the evaporator coils or surfaces 15. Theout-let end of the coil 15 is connected to opening 17 which is in turnconnected to a passageway 30 extending within cover 16 and opening intothe upper part of the float chamber. Cover 11 is also equipped with anopening 12 for connection to the suction side of the compressor. Betweenthis opening and the compressor, an evaporator portion is arranged inseries, such portion comprising, in one form, a tubular member 27.

Vithin casing 10 is a float 18 which rests upon the surface of a body ofliquid therein and in turn determines the level of liquid surfacetherein which separates the liquid space of the chamber from the vaporspace of thechamber. Changes of the surface level of liquid within thefloat chamber cause movement of float 18. This movement is transmittedthrough lever 19, bell-crank 20 and link 21 to the needle valve 22 whichcontrols the orifice of valve member 23. Needle 22 is a small diameterneedle in a relatively long bore. Hence there will be only a negligibleleakage of liquid refrigerant past the needle 22 into the float chamber.

A tube 24 is fitted into cover 11 connecting with opening 12 and withthe suction side of the compressor and extending into the casing 10within the vapor space thereof. Within tube 24 is situated a restrictedportion 31. This restricted portion is preferably formed as thecontracted portion of a Venturi tube 25. The Venturi tube has agradually contracting passageway towards the restricted portion and agradually expanding passageway away from the restricted portion as ischracteristio with Venturi tubes. The restricted portion of the Venturitube, otherwise known as the throat, has connected thereto a tube 26 ofrelatively small internal diameter or bore which extends below thesurface level of liquid refrigerant within casing 10.

The system illustrated in Fig. 1 is intended to contain a refrigerantand a lubricant of such nature that, in operation, the lubricant isdissolved in or is emulsified in the refrigerant. As an example of suchfluids, methyl chloride may be used as the refrigerant and mineral oilas the lubricant.

The mode of operation is as follows:

Refrigerant compressed in compressor 3 passes into condenser 4 where itis liquefied and thence passes through conduit 7 and into opening 13,assuming that needle valve 22 is open. Assuming needle valve 22 to beopen, liquid refrigerant passes into coil 15 and a portion isevaporated, which evaporation absorbs heat from the surroundings andproduces refrigeration. A mixture of Vaporous refrigerant and liquidrefrigerant passes through opening 17 from the evaporator coil andthrough passageway 30 into the float chamber. Rise of liquid quantitywithin the float chamber causes a lifting of float 18 and thisoperates,"through lever 19, bell-crank 20 and link "21, to close needlevalve 22 to a greater or less extent. If needle valve 22 is entirelyclosed, no liquid refrigerant passes from the condenser into opening 13and to the evaporator. time draws vapor through conduit 24 and some ofthe liquid within float chamber 10 evaporates, thus lowering the liquidlevel therein. The float 18 consequently is lowered and needle valve 22again opens to permit entry of liquid refrigerant into the evaporator.Float 18 thus operates to maintain the liquid level within the floatchamber constant or substantially constant.

The vapor passing out through Venturi tube 25 increases in velocity inthe throat 31 and there is a corresponding drop in pressure at thispoint which produces a suction acting through tube 26. This suctioncauses liquid to flow through tube 26 and into conduit 24 and thenceonto the compressor. The liquid passing through tube 26 is composed ofmethyl chloride or other refrigerant and dissolved or suspended oil. Thefluid passing through conduit 24 passes on into evaporator 7 coil 27where the liquid refrigerant is entirely vaporized and passes into thesuction line proper as a gas together with the sepa- The compressor atthe same of operation until the point is reached where the oil drawnthrough tube 26 equals the entrained oil entering the evaporatingsection. Our arrangement therefore automatically maintains a proper flowof lubricant.

The invention is not limited to suspended or dissolved lubricant. Fig. 8shows an arrangement adapted for use in a system employing sulphurdioxide having as lubricant an oil which is lighter than sulphur dioxideand which floats on thetop of the same. In this case tube 26 is extendedto the surface of liquid in the float chamber and the suction in theVenturi tube draws oil from the surface. By using a tube 26 extending tothe bottom of casing 10, as shown in Fig. 4, the invention is applicableto a refrigerating system using ethyl chloride or.methyl chloride withglycerine as a lubricant, glycerine being heavier than ethyl chloride ormethyl chloride and insoluble therein. In either of the two casesillustrated in Figs. 3 and 4, the second evaporator 21 (Fig. 1) is notnecessary as there would not be sufiicient liquid refrigerant entrainedby the lubricant and sucked up tion side of the compressor to require asecond evaporator. In these cases, opening 14 should be connecteddirectly by a pipe to the suction side of the compressor, the switchbeing interposed in this pipe.

Fig. 5 shows a restriction or orifice 41 which may be used for the samepurpose as the Venturi tube in conduit 24. When an orifice is used thetube 26 communicates with conduit 24 a short distance in the directionof flow beyond the orifice 41. The use of an orifice would cause apermanent pressure drop in the outlet conduit beyond the orifice. Suchconnection has also an asperating effect. 1

Having thus described our invention what we claim is:

- 1. Refrigerating apparatus comprising, in combination, a chamber, afloat in said chamber and means co.-operatingwith said float to define aliquidspace and,a vapor space in said chamber, a discharge connection inthe vapor space of said chamber, said connection having a restrictedportion and a communication between said restricted portion and theliquid space of said chamber.

2. Refrigerating apparatus comprising, in

fri rant within the system, a conduit within sai float chamber connectedto the compressor, a restricted portion within said conduit, and a tubeconnected to said restricted ortion and extending downwardly there romwithin said float chamber.

3. Refrigerating apparatus comprising, in combination, a float chambercontaining a float, an evaporator tube connected to said float chamber,a valve controlling the flow of fluid through said tube and in turncontrolled by said float, a conduit within said chamber adapted to beconnected to a compressor, a Venturi tube within said conduit havingarestricted throat, and a connection from said throat to a lower portionof said chamber.

4. Refrigerating apparatus comprising, in combination, a compressor, acondenser, an evaporator, said compressor, condenser and evaporatorbeing connected to form a circulating system for refrigerant andlubricant, said system including a float chamber. a float within saidchamber, a valve controlled by said float and operating to controltheflow of refrigerant within the system, a conduit connected to anupper portion of said chamher, a Venturi tube interposed in saidconduit, and a tube connected with a lower portion of said chamber andconnected to the restricted portion of said ,Venturi tube.

5. In a refrigerating apparatus, an evaporator comprising a continuousconduit.

' means to produce flow of fluid through said conduit, a valve at theinlet to saidconduit, a chamber at the exit from .said conduit, meansresponsive to variations of liquid level in said chamber operable tocontrol said valve, a discharge connection for removing vapor from onepart of said chamber, said connection having a restricted portionoperating to produce a space of diminished pressure and a communicationbetween said space of diminished pressure and a lower part of saidchamber.

6. A refrigerating system comprising, in series, a compressor. acondenser, a valve, an evaporator and a float chamber together with afloat in said float chamber.'mechanical connecting means between saidfloat and said valve. said mechanical connecting means being conta nedwholly within said system, said float, valve and connecting meanstherebetween operating to define a liquid .space and a. vapor space insaid float chamber, a discharge connection for conveying fluid from saidchamber to said compressor connected to the vapor space of said chamber.said discharge connection having a-restricted port on and acommunication between said restricted portion and the liquid space ofsaid chamber. 7. A refrigerating system comprising. 1n

- series, a compressor, a condenser, a valve. an

evaporator and a float chamber together with a float in said floatchamber, mechanical connecting means between said float and said valve,said mechanical connecting means being contained wholly within saidsystem, said float, valve and connecting means therebetween operatingtodefine a liquid space and a vapor space in said float chamber, a dischare connection for conveying fluid from said chamber to said compressorconnected to theinto said chamber, means responsive to variations ofliquid level in said chamber operable to control said valve, a dischargeconnection for removing vapor from one part of said chamber andconducting the same to the compressor, said connection being adapted onoperation of said compressor to have a diminished pressure therein and acommunication between said conduit and a lower part of said chamber forcausing the diminished pressure in said conduit to remove liquid fromthe lower part of said chamber.

9. Refrigerating apparatus comprising, in

combination, a first evaporator member, means to supply liquid to saidevaporator member, a closed vessel connected to said evaporator memberto receive liquid and vapor therefrom, means to regulate the supply ofliquid to said evaporator member to define a liquid space and a vaporspace in said vessel, a second evaporator member, a conduit connectingthe vapor space of said vessel with said second evaporator member, meansto produce a space of diminished pressure in said conduit and aconnection between said liquid space and 'said space of diminishedpressure. I c

10. Refrigerating apparatus comprising, in combination. a firstevaporator member, means to supply liquid to said evaporator member, aclosed vessel connected to said evaporator member to receive liquid andvapor therefrom, means to regulate the supply of liquid to saidevaporator member to define a liquid space and a vapor space in saidvessel, 9. second evaporator member, a conduit connecting the vaporspace of said vessel with said second evaporator member, arestrictedportion in said conduit and a connection between said liquidspace and said restricted portion.

In testimony whereof we hereunto afiix our signatures.

FRANK DE'SNOYERS PELTIER. CLYDE EDWARD PLOEGER.

